1. Field of the Invention
This invention generally relates to systems that reproduce images, and more specifically, to systems that reproduce images onto surfaces, including compound curved surfaces.
2. Description of the Related Art
Complex surfaces, including small components such as mechanical parts or large objects such as buildings, have traditionally been mapped using standard methods, including mylar transfer templates, theodolites laser trackers, and more recently, laser projectors. Generally, these methods are time consuming, tedious and may lack accuracy. For example, a laser projector may be used to project two-dimensional images onto a contoured surface. The projected images are used as patterns for manufacturing products and locating an image onto a desired location. For example, an image may be projected onto a ply manufactured for airplane fuselages, and the like. To be effective, the laser emitter must generally be positioned in an accurate and precise manner. The projector's designated points and angles, however, may not be accurately controlled. It becomes necessary to use multiple laser projector heads to accurately project the lines in their proper location, the larger the projected image and the more complex the surface it is to be projected upon. In addition, the focal length of the laser may be hindered by physical objects, i.e. floors, walls, support posts, & ceilings. If the projection head can not be placed far enough away from the object, it will be unable to project over the entire surface thus requiring more equipment or additional set-ups.
Recently, theodolites have been employed to provide for greater accuracy in determining the coordinates of the reference marks. A theodolite is a mounted optical instrument, which measures horizontal and vertical angles in space. Though it may accurately define a point from the horizontal and vertical angles of a surface relative to a given coordinate system, it typically does not indicate the object geometry, including shape, dimension, and location. Generally, a theodolite is fairly expensive, time consuming and labor intensive. Moreover, current methods of mapping complex surfaces lack the ability to print images onto complex contoured surfaces that have no physical points of reference.
A further problem in mapping and marking surfaces relates to the need to properly position and orient surface marking devices such as a printer, so that the markings are precisely applied at the correct locations on the marking surface. In those cases where a surface mounted printer is used, the feet or legs of the printer rest on the surface to be marked, which may be irregular where the surface includes compound curves. As a result, the firing column of the printing device is not perpendicular to the marking surface, causing error in the position of the applied markings.
Accordingly what is needed is a system and method for reproducing images onto surfaces in which both the spatial position and orientation of an image producing device, such as a printer, is known relative to a surface that is to be imaged or marked. The invention is directed toward satisfying this need.